DE69923590T2 - MATERIALS FOR LIQUID CONTROL IN PRODUCTS FOR PERSONAL HYGIENE - Google Patents

Description

AREA OF INVENTION

The The present invention relates to the structure in a personal care product such as diapers, training pants, absorbent underpants, products for incontinence Adult, bandages and feminine hygiene products, the one Surge of liquid be able to record.

BACKGROUND THE INVENTION

produce for the personal Hygiene includes objects such as diapers, incontinence garments and devices, bandages and products for feminine hygiene such as sanitary napkins, panty liners and tampons, and the same. The most basic version of all these products contains typically a close-fitting one Insole, an outer shell and an absorbent core disposed between the proximal insert and the outer cover is.

Products for the Female hygiene, such as sanitary napkins, have absorbent Cores, usually are designed to absorb a thick, slowly flowing liquid. Menstruating women However, they complain frequently the suffering of sudden outflows or bouts of menstrual bleeding, which comes from the body as a fluid attack with high amount and in short discharge time. An absorbent core, which is designed to handle a slow-flowing current, usually has one Too small pore structure, these spills or limited swells the liquid As a result, a fluid accumulation or puddling on the product surface can result. The accumulation on the surface can leak or stain clothing and is unacceptable to the wearer. In the other case you can absorbent materials that have a sufficiently long pore structure have to absorb the effluent quickly, this liquid not to the outer ends of the product distribute it further, thus causing the outflow fluid in the middle part of the pad or pads collects where the pressure on the side wings can cause a leak. The publication WO 92/11830 discloses an absorbent article having a fast-gathering, multilayer, absorbent core.

It It is therefore an object of this invention to provide an absorbent structure to provide the sudden surges or outflows the liquid quickly absorb the liquid move away from the top of the absorbent to the user a feeling to gain the dryness, and the liquid along the whole Length of Distribute structure further and absorb this liquid into another Can deliver layers.

SUMMARY THE INVENTION

The Objects of the invention are provided by a fluid control material complied with claim 1.

SHORT DESCRIPTION THE DRAWINGS

It demonstrate:

1 a cross-sectional view of a fiber of a capillary surface material suitable for use in the practice of this invention and prepared according to WO 93/02 235;

2 a cross-sectional view of a capillary surface material fiber suitable for use in the practice of this invention and made according to PCT / US97 / 14607;

3 further cross-sectional views of non-round fibers for use in the practice of this invention made according to US Patent 5,458,963;

4 a fluff pulp embossed with a longitudinal sine wave pattern and marked along its length in 5 zones;

5 an hourglass-shaped plate for use in a surge / distribution test;

6 a rating block device used in the surge flow test of materials.

DEFINITIONS

"Disposable" includes, after a single application to be thrown away without the intention of being washed or to be used again.

"Front" and "back" are through this Described throughout, rather the relationship to clothing mark itself as indicating any position, the the garment when positioned on a user.

"Hydrophilic" describes fibers or the surfaces of fibers passing through the water liquids are wetted, which come into contact with the fibers. The degree of Wetting of the material in turn may be in terms of contact angle and the surface tensions of included fluids and materials are described. Equipment and procedures used for Measuring the wettability of special fiber materials suitable are, can by a Cahn SFA-222 Surface Force Analyzer System or a essentially equivalent System be provided. If fibers with contact angles of less than 90 ° with In this system, they are labeled as "wettable" or "hydrophilic" while fibers with contact angles equal to or greater than 90 ° as "not wettable "or" hydrophobic ".

"Layer" can, if it as Singular is used, the double meaning of a single Have part or a variety of parts.

"Liquid" does not mean one particulate Substance and / or material that flows and the inner shape of a container can be accepted, in which it is poured or in which it is arranged.

"Fluid connection" means that yourself liquid from one layer to another layer or from one point to move to another within a shift.

Related to "particles" with this invention is, but not limited to, any geometric shapes such as spherical grains Fibers or strands, flat surfaces or roughened surfaces, Leaves, Stripes, threads, strands or similar.

"Spraying" and variations of which include strong expelled Liquid, either as a stream or as individual entities, such as swirling Threads or atomized Particles through an opening, Nozzle or the like by an applied pressure of air or another Gas, by gravitational force or by centrifugal force. Of the spray can be continuous or not continuous.

"Conjugated Fibers " Fibers formed from at least two polymers separated from each other Extrusions ejected but were spun together to form a fiber. Conjugated fibers are sometimes called multicomponent or Bicomponent fibers. The polymers differ usually of each other, although conjugate fibers monocomponent fibers could be. The polymers are in a substantially constant position, separate Zones over the Cross-section of the conjugate fibers arranged and extend continuously along the length the conjugate fibers. The design of such a conjugate For example, fiber may be a sheath / core arrangement be, wherein one polymer is surrounded by another, or can a juxtaposed arrangement, a pie array or be an "island in the sea" arrangement. Conjugated fibers are disclosed in U.S. Patent 5,108,820 to Kaneko et al., in US Patent 5,336,552 to Strack et al. and in U.S. Patent 5,382,400 to Pike et al. shown. at Two-component fibers can the polymers in proportions from 75/25, 50/50, 25/75 or any other desired conditions to be available. The fibers can also have shapes such as those disclosed in US Pat. Nos. 5,277,976 to Hogle et al. and 5 057 368 for Largman et al. be described, the fibers with unconventional Portray forms.

"Two-component fibers" refer to fibers formed from at least two polymers ejected from the same extruder as a mixture. The term "blend" is defined below. Bicomponent fibers do not have the various polymer components disposed in relatively constantly positioned discrete zones across the cross-sectional area of the fiber, the various polymers typically being non-continuous along the entire length of the fiber and instead, they usually form fibrils or protofibrils that begin and end randomly. Bicomponent fibers are sometimes referred to as multicomponent fibers. Fibers of this general type are discussed, for example, in U.S. Patent 5,108,827 to Gessner. Bicomponent and bicomponent fibers are also taught in the textbook Polymer Blends and Composites by John A. Manson and Leslie H. Sperling, copyrights 1976 to Plenum Press, a division of Plenum Publishing Corporation of New York, IBSN 0-306-30831-2 Pages 273 to 277, discussed.

"Capillary Surface Materials "or CSMs (Capillary Surface Materials) are fibers or groups of such fibers that certain liquids on their surfaces transport spontaneously can. Fibers of this general type are described, for example, in the publications PCT / US 97/14607, WO 93/0223, WO 90/12130 and in the US patents 5,268,229, 5,611,981 and 5,723,159. Likewise offer "capillary Channel fibers "a improved fluid capacity and a improved ability liquid to transport and save. Fibers of this general type are for example in documents 5,200,248 and 5,242,644.

Of the Term "machine direction" or MD (machine direction), as used here, means the length of a Fabric in the direction in which it is made. The term "cross machine direction" or CD (cross machine direction) means the width of the fabric, d. H. a direction, which is generally perpendicular to the MD.

Of the The term "spun-bonded fibers" as used here is concerned with small diameter fibers melted by the ejection, thermoplastic material as threads of a variety of fine, usually more circular Capillary vessels from one spinneret be formed, the diameter of the ejected threads then is rapidly reduced, as for example in US Patent 4,340,563 for Appel et al. and in US Pat. No. 3,692,618 to Dorschner et al., in US Pat 3 802 817 for Matsuki et al. and in U.S. Patents 3,338,992 and 3,341,394 to Kinney, in US Patent 3,502,763 to Hartman and U.S. Patent 3,542,615 to Dobo et al. Spunbond fibers are generally not sticky when applied to a quilt become. Spunbonded fibers are microfibers, are generally continuous and have average diameter (from a sample of at least 10), which is greater than 7 microns, more specifically between about 10 and 35 microns are. The fibers can Furthermore Shapes such as those disclosed in U.S. Patent 5,277,976 to Hogle et al., in U.S. Patents 5,466,410 to Hills and 5,069,970 and 5 057 368 for Largman et al. described the fibers with unconventional Portray forms.

Of the Term "melt-blown Fibers, "he said used here means fibers that by ejecting a molten thermoplastic material through a variety of fine, usually circular Form capillaries as melted yarns or threads in converging, usually hot, with high speed flowing Gas (eg air) streams be formed, which the threads make the molten thermoplastic material thinner about its diameter reduce, which can be a microfiber diameter. After that The lard-blown fibers are passed through at high speed flowing Gas flow transported and on a quilt Applied to a tissue of random finely divided, lard-blown To form fibers. Such a method is described for example in US Patent 3 849 241 for Butin et al. disclosed. Meltblown fibers are microfibers, which can be continuous or not continuous, the are generally less than 10 microns in average diameter and which are generally sticky when applied to a quilt become.

The "airflow method" is a well-known method by which a fibrous, nonwoven layer can be formed. In the airflow process, bundles of small fibers having typical lengths in the range of about 3 to about 52 millimeters are separated, entrained in an air supply, and then buried The randomly applied fibers are then bonded together by means of, for example, hot air or a spray adhesive The air flow method is described, for example, in U.S. Patents 4,005,957, 4,388,056, 4 592 708, 4 598 441, 4 674 996, 4 761 258, 4 764 325, 4 904 440, 4 908 175 and 5 004 579, in the German patent DE 3 508 344 A1 , in European Patent Application 85300626.0 and British Patent Application 2,191,793.

As used herein, the term "co-forming process" means a process in which at least one melt-blown die head is positioned near a groove through which other materials are added to the fabric as it is being formed other materials may be pulp, superabsorbent polymers or other particles, natural polymers (for example rayon or cotton) and / or synthetic polymer fibers (for example polypropylene, polyester, polyamide or acrylic) where, for example, the fibers have typical lengths in the range of about 3 to may have about 52 millimeters in length. Coforming processes are described in commonly assigned US Pat. Nos. 4,818,474 to Lau and 4,100,324 to Anderson et al. shown. Fabrics produced by the coforming process are generally referred to as coforming materials.

"Composite carding fabric" refers to tissue, made of staple fibers, where the typical fiber lengths ranging from about 19 to about 52 millimeters in length. These fibers are going through a combing or clutter unit sent the staple fibers apart breaks and aligns in the machine direction to one in general machine-oriented, fibrous nonwoven fabric. The tissue is known by one or more of various Binding method connected.

The Binding of nonwoven fabrics can be accomplished by a number of methods become; Powder binding, with a powdered adhesive through the tissue is distributed and then usually by heating the tissue and the adhesive with hot air is activated; Profile bonding, wherein heated calender rolls or a Ultrasonic binding device can be used to place the fibers in usually to connect a locally established connection pattern, through that the tissue over his entire area can be connected if so desired; Through-air-binding, wherein air that is sufficiently warm is at least one component softening the tissue through which tissue is directed; chemical Binding by means of, for example, latex adhesives, which affect the tissue for example by spraying be applied; and solidification by mechanical processes, like needles and hydro-webs.

"Products for the personal Hygiene "mean Diapers, training pants, absorbent underpants, products for incontinence Adult, products for feminine hygiene and wound care products such as bandages and Bandages.

"Products for female Hygiene "mean Sanitary napkins or burps or tampons.

"Target area" refers to the area or the position on a product for personal hygiene, at the one Seizure is usually delivered by a user.

TEST METHODS AND MATERIALS

material caliber (Thickness) The caliber of a material is the measure of thickness and becomes 344.7 Pa (0.05 psi) measured with a Starret volumeter in millimeter units.

Density The density of the material is calculated by dividing the weight per unit area in grams per square meter (g / m ² ) by the volume of the sample in millimeters (mm) at 344.7 Pa and multiplying the result by 0.001, by the value in grams per cubic centimeter (g / cm ² ). In total, three samples were evaluated and the average value for the density values was determined.

Schwall / Werteilung: This surge and distribution test tries the ability of an absorbent material, both with the continuous, slow flow as well as with the sudden Flow to deal with a high volume surge. In addition, the test measures the effectiveness a system of absorbent material to the liquid along its length to move.

A piece of the absorbent material or material system to be evaluated is cut to 1.5 inches (38 mm) wide by 6 inches (152 mm) long and marked in 5 equal zones along its length. A desorbing flake material used herein is cut into a rectangular, 3 inch (76 mm) wide and 6 inch (152 mm) long piece. The desorbing material used herein is a fluff pulp (CR0054 from Coosa Mills of Coosa, Alabama) of 600 g / m ² , which has a longitudinal sine wave pattern according to US Pat 4 is characterized. The desorbing flake material is also marked in 5 equal zones along its length. All materials should be weighed before the test begins. The 38 mm (1.5 inch) wide test sample is placed on the desorbing material and centered evenly across the width so that it matches the longitudinal dimensions of each layer. A plate in the shape of an hourglass according to 5 (not to scale) is placed on the test sample so that its longest dimension matches the longitudinal dimension of the material. The hourglass plate is 8.25 inches (210 mm) long, 0.5 inches (13 mm) thick, with 3.375 inches (86 mm) at each end wing and 3 inches (76 mm) at the center in the middle a hole with a diameter of 7 mm, weighs about 240 grams and is preferably made of a plastic, such as PLEXIGLAS plastic, as used herein.

The most difficult challenge for an absorbent material or material system is still to soak up the liquid as quickly as the absorbent absorbs some liquid, as it did when the material was dry and unused. Testing the wick absorption time by means of a partially saturated, absorbent system is a criterion that challenges more than that found by testing a dry sample. This test procedure begins with pre-saturating the assembled absorbent layers. A continuous, slow stream of 5 ml of artificial menses is delivered to the absorbent sample. To deliver artificial menses (prepared as shown below) into the opening in the middle of the hourglass plate at a rate of 10 ml / hr for 30 minutes, a syringe pump and a section of tubing are used. The inventors used a 30 cm ³ syringe (catalog no. 301626) from Becton Dickinson of New Jersey, which on a programmable syringe pump (catalog no. 70-2002) from Harvard Apparatus, South Natick, Massachusetts with a Harvard PHD 200 multiple Syringe, although any equivalent delivery device would be suitable. A length of flexible TYGON ^® tube that about 6 to 8 inches (15 to 20 cm) measured from Norton Performance Plastic Corporation, Akron, OH (catalog no. AAB00006, 0.125 inch (3.175 mm) inner diameter 0.1875 (4.7625 mm) outer diameter, 0.03125 inch (0.8 mm) wall thickness) is connected at one end to the syringe, with its opposite end inserted into the opening in the middle of the hourglass plate to the absorbent System to supply liquid. If the artificial menses overflows from the opening in the hourglass plate during the 30 minutes, it should be picked up with a paper towel whose weight is known. After 30 minutes, the addition of artificial menses is stopped, recording the weights of the paper towel containing the overflow, the desorbing material and the test sample.

The desorbing material and the sample (without the hourglass plate) are reassembled in the same orientation as during the 30 minute addition of liquid and left undisturbed for 5 minutes. Next, the system is insulted with a surge of liquid, recording its wicking time. Regarding 6 For example, a design block as illustrated is placed in the center on top of the test material and its desorbing fluff composition. The design block 10 is 3 inches (76.2 mm) wide and 2.87 inches (72.9 mm) deep (in the leaf) and has a total height of 1.125 inches (28.6 mm), which is a mid-range 19 on the underside of the rating block 10 that of the main body of the design block 10 protrudes further and has a height of 0.125 inches (3.2 mm) and a width of 0.886 inches (22.5 mm). The design block 10 has a capillary tube 12 with an inside diameter of 0.186 inches (4.7 mm), extending from one end 15 diagonally down to the middle line 16 extends at an angle of 21.8 degrees to the horizontal. The capillary 12 can by drilling the opening of an appropriate size from the side 15 of the design block 10 be made at an appropriate angle, starting at a point 0.726 inches (18.4 mm) above the bottom of the design block 10 lies; provided, however, that the starting point of the borehole in the side 15 then must be blocked, so that the test liquid will not escape there. The upper hole 17 has a diameter of 0.312 inches (7.9 mm) and a depth of 0.625 inches (15.9 mm), making it the capillary 12 cuts. The upper hole 17 is at right angles to the top of the dimension block 10 and is 0.28 inches (7.1 mm) from the side 15 arranged in the middle. The upper hole 17 is the opening into which the funnel 11 is placed. The center hole 18 is there to observe the course of the test fluid and actually has an oval shape in the plane of the capillary 12 , The borehole 18 is widthwise on the design block 10 centered and has a bottom hole width of 0.315 inches (8 mm) and a length of 1.5 inches (38.1 mm) from center to center of the 0.315 inch (8 mm) diameter semi-circles that make up the ends of the oval , The oval increases over 0.44 inches (11.2 mm) from the bottom of the design block 10 to a width of 0.395 inches (10 mm) and a length of 1.930 inches (49 mm) to facilitate viewing. The upper hole 17 and the center hole 18 can also be made by drilling.

One Surge of 2 ml artificial Menses fluid, which has been prepared as described below, will drill in the Rated block supplied by means of a micropipette, with a timer or a stopwatch is started. The timer is stopped when the whole liquid was absorbed into the material or material system, as by the chamber is observed in the test device. The design block is removed and the test sample and the desorbing material weighed, to the liquid distribution between each shift. The test sample and the desorbing Material is cut along the markings, with each one Zone is weighed. Then a distribution ratio for each layer can be considered the average the mass of the two end zones divided by the mass of the central zone be calculated.

The distribution ratio can be seen as:
(Liquid in zone A + liquid in zone E) / 2 divided by (liquid in zone C)

To meet the requirements of the present invention, an absorbent material system must provide an acceptable surge wicking time as well as an acceptable distribution ratio. The break through time to absorb the soak time required for a partially saturated absorbent material system to a sudden surge of 2 cm ³ liquid which has been applied to its uppermost surface. A short soak time therefore indicates that the material system will easily pick up the liquid. The distribution ratio is a measure of how well a fluid system can move fluid along its length after a surge. The higher the distribution ratio, the better the material has distributed the liquid along the length of the product.

Preparation of Artificial Menses: The artificial menses was prepared from blood and egg white (according to US Patent 5,883,231) by separating the blood into plasma and red cells and separating the egg whites into thick and thin pieces. "Dick" means that it has a flowability after homogenization of above about 20 centipoise at 150 sec ^-1 , whereby the thick egg white is bound to the plasma and mixed vigorously, and finally the red cells are added and mixed vigorously. defibrinated porcine blood in this example was separated by centrifugation at 3000 rpm for 30 minutes, although other procedures or rotations and times may be used if effective: the plasma was divided and stored separately, the buffy coat was removed and discarded, It should be noted that the blood needs to be treated in some way so that it can be processed without clotting, and various methods such as defibrinating the blood are clogged to those of skill in the art to remove fibrous materials, the addition of anticoagulant chemicals and more known. The blood must not be clotting to be usable, and any method that does so without damaging the plasma and the red cells is acceptable.

Huge chicken eggs were separated, egg yolks and chalazae (hail cords) were discarded and the egg whites kept. The protein was separated into thick and thin pieces by filtering the egg white through a 1000 micron nylon mesh for 3 minutes, discarding the thinner part. The thick portion of egg white which was retained on the mesh was collected and drawn into a 60 cm ³ large syringe which was then placed on a programmable syringe pump and homogenized by expelling and refilling five times of the content. The extent of homogenization was controlled by the syringe pump rate of about 100 ml / min and the tubing inner diameter of about 0.12 in (3 mm). After homogenization, the thick egg white had a flowability of about 20 centipoise at 150 sec ^-1 and was then placed in the centrifuge and rotated for about 10 minutes to remove residual particles and air bubbles at about 3000 rpm.

After centrifuging, the thick, homogenized egg white was containing Ovamuzin, a 300 cm ³ major FENWAL ^® transfer pile containers fed by means of a syringe. Then the FENWAL ^® Transfer stacking containers were added to 60 cm ³ of porcine plasma. The FENWAL ^® Transfer stack container was clamped, all air bubbles removed, and placed in a Stomacher Laboratory Mixer, where it was mixed at normal (or medium) speed for about 2 minutes.

The FENWAL ^® Transfer stacking container was then removed from the mixer, 60 cm ³ red blood cells from pigs were added and the contents by kneading by hand for about 2 minutes, or until the contents appeared homogenous mixed. A hematocrit from the last mixture indicated a red blood cell content of about 30% by weight, generally being at least in the range of 28-32% by weight for the artificial menses prepared according to this example.

• Blut (Schwein): Cocalico Biologicals, Inc., 449 Stevens Rd., Reamstown, PA 17567, (717) 336–1990.
• FENWAL^® Transfer Stapelbehälter, 300 ml, mit Anschlussstück, Code 4R2014: Baxter Healthcare Corporation, Fenwal Division, Deerfield, IL 60015.
• Harvard Apparatus Programmable Syringe Pump, Model Nr. 55-4143: Harvard Apparatus, South Natick MA 01760.
• Stomacher 400 Labormixer, Model Nr. BA 7021, Seriennummer 31968: Seward Medical, London, England, UK.
• 1000 Mikron-Maschennetz, Erzeugnis-Nr. CMN-1000-B: Small Parts, Inc., PO Box 4650, Miami Lakes, FL 33014-0650, 1-800-220-4242.
• Hemata Stat-II Vorrichtung zum Messen von Hämokriten, Serien-Nr. 1194Z03127: Separation Technology, Inc., 1096 Rainer Drive, Altamont Springs, FL 32714.

The ingredients and the equipment used in the preparation of artificial menses are readily available. Below is a list of sources for the items used in this example, although of course other sources may be used, provided that they are equivalent.

• Blood (Pig): Cocalico Biologicals, Inc., 449 Stevens Rd., Reamstown, PA 17567, (717) 336-1990.
• FENWAL ^® Transfer Stacking Container, 300 ml, with connector, code 4R2014: Baxter Healthcare Corporation, Fenwal Division, Deerfield, IL 60015.
• Harvard Apparatus Programmable Syringe Pump, Model No. 55-4143: Harvard Apparatus, South Natick MA 01760.
• Stomacher 400 Laboratory Mixer, Model No. BA 7021, Serial No. 31968: Seward Medical, London, England, UK.
• 1000 micron mesh, product no. CMN-1000-B: Small Parts, Inc., PO Box 4650, Miami Lakes, FL 33014-0650, 1-800-220-4242.
• Hemata Stat-II Device for measuring hemocrits, serial no. 1194Z03127: Separation Technology, Inc., 1096 Rainer Drive, Altamont Springs, FL 32714.

DETAILED DESCRIPTION OF THE INVENTION

absorbent Products for the personal Hygiene includes such items as diapers, training pants, Incontinence garments and devices, bandages, feminine care products such as sanitary napkins, Panty liners and tampons, and the like. The most basic execution of all containing these products a close-fitting Insole, an outer shell and an absorbent core disposed between the proximal insert and the outer cover is.

Products for the Female hygiene such as sanitary napkins have absorbent Cores that are conventional are designed to absorb a thick, slowly flowing liquid. Menstruating women However, they complain frequently the suffering of sudden outflows or bouts of menstrual bleeding, which comes from the body as a fluid attack with high amount and in short discharge time. An absorbent core, that is designed to handle a slow-moving flow usually has Too small a pore structure, these spills or limited swells the liquid As a result, a fluid accumulation or puddling on the product surface can result. The accumulation on the surface can leak or stain clothing and is unacceptable to the wearer. In the other case you can absorbent materials that have a sufficiently long pore structure have to absorb the effluent quickly, this liquid usually not to the extreme Distribute ends of the product, which leads to the outflow fluid collects in the middle part of the bulge, where the pressure on the side wings a Can cause leakage.

What needed and provided by this invention is an absorbent Structure, the sudden outflows or spills of liquid quickly absorb the liquid pull away from the upper part of the absorbent to the user a feeling the dryness to reach the liquid along the whole Length of Distribute structure further and optionally transfer the liquid to other then, can deliver absorbent layers. While the invention mainly products for the Regarding feminine hygiene, the inventors believe that the starting material also in the control of other body fluids how urine could work and especially for highly viscous liquids like BM (faeces) and wound exudates effectively and so in diapers, training pants, Incontinence garments and devices, bandages and the like will be included.

One Product for the personal Hygiene is close to the body Layer, optionally a liquid transfer layer, a liquid retention layer and a garment-close layer. It can also be a distribution layer or have more optional layers to perform specialized tasks provide.

The body-hugging Layer is sometimes considered a close-fitting Insole or top sheet called. In the thickness direction of the product the lining material is the layer that lies against the skin and so the first layer, with liquid or other excretions of the user comes into contact. The Inlay also serves to remove the user's skin from the fluids, which are held in an absorbent structure to isolate and should be compatible be, feel soft and not annoying be.

The body-hugging Insole can with a selected amount of a surface-active Stoffes be treated or otherwise processed to the desired To impart levels of wettability and hydrophilic property. If a surface active Substance is applied, it can be an internal additive or it can be applied to the layer by any conventional means, such as spraying, painting and the like are applied before applying the next layer become.

The garment-facing layer, also referred to as the backsheet or outer cover, is the farthest layer from the wearer. The outer shell has usually been formed from a thin, thermoplastic film, such as a polyethylene film, which is substantially impermeable to liquid. The outer shell acts to prevent body exudates contained in the absorbent structure User's clothing, bedding or other materials in contact with or near the personal hygiene product should be moistened or soiled. The outer shell may be embossed and / or frosted to provide a more aesthetically pleasing appearance. Other alternative embodiments for the outer cover include woven or nonwoven fibrous webs constructed or treated to impart the appropriate level of fluid imperviousness or laminates formed of woven or nonwoven fabric and a thermoplastic film. The outer shell may optionally be made of a vapor or gas permeable, microporous, "breathable" material that is permeable to vapors or gas, but substantially impermeable to liquids Breathability may be imparted to the polymer films, for example, by the use of fillers in the formulation of film polymers, extruding the filler / polymer formulation into a film, and then letting the film stretch sufficiently to form voids around the filler particles, thereby making the film breathable The higher the degree of breathability, the greater the degree of breathability, and the higher the amount of stretch, The backs may also serve as a function of a mechanical fastener adapter, for example in the case where a non-woven fabric is the outer surface.

The Fluid retention layer or layers must liquid from the adjacent, body-close Absorb layer in a controlled manner, leaving liquid from contact with the body can be stored away. This must be synonymous with conditions of Waves happen. It was invented a composite structure, the slightly sudden Spills or spills of liquids absorb this liquid from the body close Remove the liner, the liquid along the length the retention layer distribute and the liquid lead into a lower layer That can either be considered the last destination for the liquid or as a transmission area affects the liquid to move into another absorbent layer, from the seizure area is removed.

The composite structure according to the invention preferably has at least three fibrous layers; an upper or first fibrous layer having a relatively low density adjacent to and in fluid communication with, and preferably in fluid communication with, a predominantly oriented surface fiber, middle layer, which in turn is substantially aligned with a lower or second layer adjacent fibrous layer with a relatively higher density and are in fluid communication with her. The first layer of low density is said to provide good fluid wicking from a slow, continuous fluid flow as well as a sudden surge. By relatively low density is meant a density between about 0.02 and 0.14 g / cm ³ . In the second fibrous layer, the relatively higher density indicates a density higher than the density of the upper layer. The second fibrous layer desorbs the layer with the aligned surface fibers, regenerating the pore space in the middle layer and allowing the aligned fibers to continue transporting more liquid along the product length. The second higher density fibrous layer is preferably homogeneous in its resistance to liquid flow, that is, the lower layer need not contain regions that provide high and low resistance to fluid flow.

The upper and lower fibrous layers may consist of predominantly hydrophilic, synthetic fibers, natural Fibers and binders or a combination of such fibers accordingly the manufacturing process for fibrous webs known to those skilled in the art and the spun-bonding process, the melt-blow process, the coforming process, the composite carding web process, the airflow process and include the formation of wet ripped paper towels. The upper and lower fibrous layers can be from the same or produced from different development processes for non-woven fabric become.

The middle layer interposed between the first (or upper) low density layer and the second (or lower) higher density layer acts to desorb the top layer and then evenly distribute the liquid along the length of the product. The oriented surface fibers may be uniformly dispersed throughout the width of the layer. However, the inventors have discovered that the most efficient use of the fluid transport capability of oriented surface fibers occurs when the fibers are oriented longitudinally of the product and spaced in one or more narrow tufts or bundles across the material width. These bundles reflect the longitudinal zones or strips of high levels of the basis weight of the fibers and the fibrous surface area and areas of small inter-fiber spacing for increased wicking distance and the volume of liquid transported along the product length. The number of bundles and the number of threads per bundle depends on the chemistry of the body fluid being transported and its existing volume hang. For high fluid volume applications such as diapers, incontinence products, and training pants, more bundles and more sutures will be needed.

The surface layer Aligned fibers or layers may be predominantly hydrophilic, synthetic Fibers, natural Fibers and binders that take the form of round or shaped fibers from staple or continuous filaments, capillary surface materials and continuous filament fibers, capillary channel materials and continuous filament fibers, superabsorbent fibers from continuous threads, stabilized staple fiber tow or splinter and other highly oriented, hydrophilic nonwoven fibrous webs, such as composite carded webs, oriented enamel-bladder tissue, constricted, stretched non-woven Fabric or a combination of such fibers, threads and layers be. Methods for making such layers include those for the Generation of the first and second fibrous layers. aligned surface fibers can Monocomponent fibers, bicomponent fibers and conjugated fibers be.

The Layer containing the oriented surface fibers in the practice of Contains invention may comprise fibers of different denier strengths. The layer may comprise fibers with a single denier or a mixture of denseness starches, being believed by the inventors to be satisfactory working the area is quite wide. The application of a mixture of the starches in The layer can improve the wicking behavior of the layer as well as a structural stability add to the layer.

In order to produce a successful personal hygiene product by the present invention, it is believed that at least 2 square meters of surface area of aligned surface fibers is required. While at first glance this seems to be a large number for relatively small products such as feminine care pads, there is a large surface area per unit length. The oriented fibers should be placed in a product in a direction that is substantially flush, ie; More than 75 percent of the hydrophilic fibers are aligned in the same direction, which is plus or minus 30 degrees to the direction of travel of the fluid that is desired. The fibers may be arranged in concentrated strips or zones so that they are close to each other to increase the wicking. These strips or zones can each be up to 20 mm wide and should have a minimum basis weight of about 50 g / m ² . Depending on their size, the physical properties of the particular fluid being treated, and the volume of fluid to be treated, multiple strips or zones may be used in a product.

conjugated and bicomponent fibers provide the ability to heat the fabric, for example, over thermal Stabilize bandages. In thermal bonding, these fibers act as binders or adhesives that hold the other fibers, for integrity of the tissue increase. These fibers support Furthermore the transfer of liquid between the layers. Such fibers can be in any or all Layers of a product are used.

In addition, in the second fibrous layer of superabsorbent particles and fibers used to be a definitive one fluid retention provide. However, it is important to note that the amount of the high absorbency polymer in a lower layer must be because a surplus crowd overflowed and the measure of Wicking effect in the middle layer of the aligned surface fibers occurs, will reduce significantly. An effective amount of the high absorbency active polymer, in whatever form, the amount that makes it possible that the wicking continues.

High absorbency active polymers useful in the present invention may be selected from classes based on a chemical structure as well as a physical form. These include high gel absorbency, high gel strength, surface-crosslinked high absorbency active polymers, uniformly crosslinked high absorbency active polymers or high absorbency active polymers with varying coverage density throughout the structure. High absorbency active polymers are based on chemical compositions including, but not limited to, acrylic acid, isobutylene / maleic anhydride, polyethylene oxide, carboxylmethyl cellulose, polyvinyl polypyrrolidone and polyvinyl alcohol. The high absorbency active polymers range in speed from slow to fast. The high absorbency active polymers may be in the form of foam, macroporous or microporous particles or fibers and may have fuzzy or fibrous coatings or a morphology. The high absorbency active polymers may take the form of tapes, particles, fibers, sheets or films. High absorbency active agents may exist in various lengths and diameter sizes and distributions. The high absorbency active polymers may be in various degrees of neutralization. Neutralization occurs through the use of counter-ions such as Li, Na, K, Ca. Examples of these types of high absorbency active polymers can be found in Stock get live Inc. under the trade name FAVOR ^® 880th Examples of these types of superabsorbents that you get at Camelot are recognized as FIBERDRI ^® 1241 and FIBERDRI ^® 1,161th Examples of these types of high absorbency active polymers obtained from Technical Absorbents Ltd. gets recognized as Oasis 101 and Oasis 111. Another example, which is included in these types of superabsorbents, you can get at Chemdall Inc. and is designated as Flosorb ^® 60 Lady. Another example, which is included in these types of superabsorbents, one gets from Sumitomo Seika of Japan and is referred to as SA60N Type ^®. 2 Also, additional high absorbency active polymers not listed herein may be useful in the present invention which are generally available and known to those skilled in the art.

The Laminates of this invention can by producing each layer separately and then assembling them become. Alternatively, it is also possible such layers in a continuous, concurrent process directly to each other to produce. In any case, it is necessary to put the layers together in any way that a fluid connection between the layers possible is.

Such Connection can be made, for example, by binding by air, thermal Binding, adhesive bonding and the like are carried out as described above is. The running process can be a simple thermal bonding between the layers, when generated, without any additional, separate connection steps. It can be any method of joining the layers so that the Fluid communication is admitted and which is known in the art, be applied.

The Structures of this invention may made of different materials including synthetic fibers, Natural fibers, binders and oriented surface fibers getting produced.

synthetic Fibers include those made from polyamides, polyesters, rayon, Polyolefins, acrylics, high absorbency active polymers, lyocel-regenerated ones Cellulose and any other suitable synthetic fibers were prepared and which are known in the art. synthetic Fibers can Furthermore Cosmotropes for decomposition of the product included.

Natural fibers include wool, cotton, flax, hemp and wood pulp. pulps include a common one Softwood flocculation class such as Coosa Mills CR-1654, high volume, additional, formaldehyde-free pulp (high-bulk additive formaldehyde free pulp - HBAFF), available at Weyerhaeuser Corporation of Tacoma, WA, which is a networked one Pulp fiber from southern Softwood with enriched wet modulus is, and a chemically cross-linked Pulp fiber like Weyerhaeuser NHB416. HBAFF goes through a chemical Treatment, in addition for increasing the dry and wet stiffness and elasticity of the fiber a curling and twisting. Another suitable pulp is Buckeye HP2 pulp and another is IP Supersoft of International Paper Corporation. Suitable rayon fibers are 1.5 denier Merge 18453 fibers from Acordis Fibers (formerly known as Courtaulds Fibers Incorporated) from Axis, Alabama.

Binders include fiber, liquid or other binder devices that can be thermally activated. Exemplary binders include conjugated fibers of polyolefins and / or polyamides and liquid adhesives. Two such suitable binders are sheath, core-conjugated fibers identified as KoSA Inc. (formerly Trevira Inc. and previously Hoechst-Celanese), PO Box 4, Salisbury, NC 28145-0004, designated T-255 and T-256 although many binder fibers are known to those skilled in the art and are produced by many manufacturers, such as ES FiberVisions Inc. A suitable liquid binder is Kymene® 557LX binder ^®, available from Hercules Inc. of Wilmington, Delaware.

aligned Surface fibers, like the capillary surface materials in the preferred case, which can spontaneously transport certain liquids For example, in PCT / US 97/14607, the European patent application 0 391 814 A2 and US Pat. Nos. 5,200,248, 5,242,644, 5,268,229, 5,611,981 and 5,723,159.

Document PCT / US97 / 14607 describes a fiber bundle comprising at least two fibers which only weakly transport liquids when acting as single fibers, but when bundled, the fibers provide a bundle which excellently transports the liquids , The bundle has a specific volume greater than 4 cubic centimeters per gram (cm ³ / g), an average capillary width between the fibers of 25 to 400 microns and a length which is greater than one centimeter (cm). At least one of the at least two fibers has a non-circular cross section, a single fiber volume factor greater than 4.0, a specific capillary volume less than 2 cm ³ / g and is more than 70% of intrafiber channels with a capillary channel width which is greater than 300 microns. Preferably, the cross section defines a first arm having a length of more than 40 microns. The lengths of the cross section of the fibers are in the range up to almost 1000 microns, with some arm lengths ranging between 100 and 400 microns. The fibers preferably have a thickness of between 15 and 250 denier. 2 showed a fiber that meets the requirements of this patent application.

wobei Pw der benetzte Durchmesser der Faser und r der Radius des umschriebenen Kreises, der den Faserquerschnitt umschreibt, und D die Abmessung der Nebenachse über den Faserquerschnitt ist. 3 zeigt eine Faser, die den Anforderungen dieser Patentanmeldung entspricht.European Patent Publication 0 391 814 A2 describes fibers which can spontaneously transport water on their surface. This fiber satisfies the equation: (1-X cos θ 3 ) <0 where θ _{3 is} the advancing contact angle of the water measured on a flat film made of the same material as the fiber and having the same, if any, surface treatment, where X is a shape factor of the fiber cross section that satisfies the following equation :

where Pw is the wetted diameter of the fiber and r is the radius of the circumscribed circle circumscribing the fiber cross section, and D is the dimension of the minor axis across the fiber cross section. 3 shows a fiber that meets the requirements of this patent application.

It became a set of examples with different materials carried out, which fulfill the object of the invention and which are described in detail below become. Note that Examples 2 and 7 are comparative and are not examples according to the invention.

example 1

The top layer was an airlaid material, which consisted of 80 weight percent pulp and 20 weight percent binder fibers having a basis weight of about 75 g / m ² and a density of about 0.04 g / cm ^3. The pulp was NB-416 manufactured by Weyerhaeuser, the binder fiber being Type ES-C manufactured by ES FiberVsions Inc. (formerly known as Danaklon of Varde, Denmark, Chisso Corp. of Japan and / or Hercules Inc. of Wilmington, Delaware).

The oriented surface fiber layer consisted of molded polyester fibers according to the document PCT / US97 / 14607 with more than 100 threads per pad and more than 60 per thread.

The lower layer was an airlaid material, which consisted of 90 weight percent pulp and 10 weight percent binder fibers having a basis weight of about 75 g / m ² and a density of about 0.08 g / cm ^3. The pulp was NB-416 from Weyerhaeuser, with the binder fiber being Type 255, 2.8 denier, from KoSa Inc. of Charlotte, North Carolina.

Example 2 (comparative)

The top layer was an airlaid material, which consisted of 80 weight percent pulp and 20 weight percent binder fibers having a basis weight of about 75 g / m ² and a density of about 0.04 g / cm ^3. The pulp was NB-416 from Weyerhaeuser, the binder fiber being Type ES-C from ES FiberVisions Inc. There was no oriented surface fiber layer in this composite structure.

The lower layer was an airlaid material, which consisted of 90 weight percent pulp and 10 weight percent binder fiber having a basis weight of about 75 g / m ² and a density of about 0.08 g / cm ^3. The pulp was NB-416 from Weyerhaeuser, the binder fiber being Type 255 from KoSa Inc. of Charlotte, North Carolina.

Example 3

The top layer was an airlaid material, which consisted of 40 weight percent pulp, 30 weight percent polyester fiber and 30 weight percent binder fiber having a basis weight of about 65 g / m ² and a density of about 0.04 g / cm ^3. The pulp was NB-416 from Weyerhaeuser, the sheath, core-conjugated binder fiber was Type 255 from KoSa Inc. of Charlotte, North Carolina and the Polyes terfaser was Type 295, 6 den, also from KoSa Inc.

The oriented surface fiber layer consisted of molded polyester fibers according to the document PCT / US97 / 14607 with more than 100 threads per pad and more than 60 per thread.

The lower layer was an airlaid material, which consisted of 90 weight percent pulp and 10 weight percent binder fiber having a basis weight of about 75 g / m ² and a density of about 0.08 g / cm ^3. The pulp was NB-416 from Weyerhaeuser, the shell, core-conjugated binder fiber Type 255 being from KoSa Inc. of Charlotte, North Carolina.

Example 4

The upper layer was a composite-carded-web material consisted of 40 percent by weight polyester fiber and 60 weight percent binder fiber having a basis weight of about 55 g / m ² and a density of about 0.025 g / cm ^3. The polyester fiber was Type 295, 6 den, wherein the shell, core-conjugated binder fiber was Type 255, both from KoSa Inc. of Charlotte, North Carolina.

The oriented surface fiber layer consisted of molded polyester fibers according to the document PCT / US97 / 14607 with more than 100 threads per pad and more than 60 per thread.

The lower layer was an airlaid material, which consisted of 86 weight percent pulp and 14 weight percent binder fiber having a basis weight of about 80 g / m ² and a density of about 0.07 g / cm ^3. The pulp was NB-416 from Weyerhaeuser, the binder fiber being Type 255 from KoSa Inc. of Charlotte, North Carolina.

Example 5

The top layer was an airlaid material, which consisted of 90 weight percent pulp and 10 weight percent binder fiber having a basis weight of about 65 g / m ² and a density of about 0.03 g / cm ^3. The pulp was NB-416 from Weyerhaeuser, the binder fiber being Type 255 from KoSa Inc. of Charlotte, North Carolina.

The oriented surface fiber layer consisted of molded polyester fibers according to the document PCT / US97 / 14607 with more than 100 threads per pad and more than 60 per thread.

The lower layer was consisted coformiertes a material consisting of 50 weight percent pulp and 50 weight percent melt-blown fiber of polypropylene microfiber having a basis weight of about 75 g / m ² and a density of about 0.09 g / cm ^3. The pulp was Weyerhaeuser CF405 to obtain the polypropylene polymer under the trade designation Montell PF-015 from Montell USA Inc. having offices in Wilmington, Delaware.

Example 6

The top layer was an airlaid material, which consisted of 80 weight percent pulp and 20 weight percent binder fiber having a basis weight of about 65 g / m ² and a density of about 0.04 g / cm ^3. The pulp was NB-416 from Weyerhaeuser, the binder fiber being Type ES-C from ES FiberVsions Inc. The oriented surface fiber layer consisted of round polyester fibers with more than 100 threads per pad and more than 3 denier per thread.

The lower layer was an airlaid material, which consisted of 90 weight percent pulp and 10 weight percent binder fiber having a basis weight of about 75 g / m ² and a density of about 0.08 g / cm ^3. The pulp was NB-416 from Weyerhaeuser, the binder fiber being Type 255 from KoSa Inc. of Charlotte, North Carolina.

Example 7 (comparative)

This single-layer fabric was consisted an airlaid material composed of 90 weight percent pulp and 10 weight percent binder fiber having a basis weight of about 250 g / m ² and a density of about 0.14 g / cm ³ spec. The pulp was NB-416 from Weyerhaeuser, the binder fiber being Type 255 from KoSa Inc. of Charlotte, North Carolina.

In In all multilayered examples, the layers were thermal Connecting by air, in the order described, with each other connected. The materials were made according to the swell / distribution test tested, with the results shown in Table 1.

Table 1

As can be seen from these results, absorb the composite structures This invention a surge quickly, especially in comparison to (Comparative) Example 7, since the breakthrough time was measured has been. Acceptable breakthrough times for personal hygiene products should be less than 40 seconds. The results of the distribution ratio show that materials that are aligned surface fibers contained in a composite material, liquids along its length very well which also leads to distribution ratios above 0.06 in all cases. This distribution ratio generated in conjunction with a penetration time of less than 40 seconds a product that delivers superior performance offers.

Claims (22)

A fluid management material for personal care products, that contains a structure, which artificial Menses according to the herein distributed swirl / distribution test distributed, and thereby a Distribution rate of at least about 0.06, and wherein the structure has a breakthrough time of less than 40 seconds. The material according to claim 1, in which the structure has at least 2 square meters of surface area of the capillary surface material having. A personal care product, which contains the structure of claim 2. The body care product according to claim 3, in which more than 75% of fibers of the capillary surface material are aligned in the same direction. The personal care product of claim 3, wherein fibers of the capillary surface material are arranged in at least one zone, each zone being at most 20 mm wide and having a basis weight of at least 50 g / m ² . A feminine hygiene insert that makes up the structure Claim 5 contains. The fluid management material according to claim 1, which in addition contains a fibrous receiving layer. The fluid management material according to claim 7, which in addition a second fibrous layer which adheres to one of the receiving layers opposite Page is located and a higher density owns as the recording layer. The fluid management material according to claim 8, wherein the second layer embossed is. The fluid management material according to claim 8, wherein the second layer is embossed with a sine wave pattern. The fluid management material according to claim 10, in which the layers are joined together by an adhesive binder. The fluid management material according to claim 8, wherein at least one layer produced by a method is, selected from the group consisting of the spunbonding process, the meltblown process, the coforming process, the method for producing a bonded, carded structure, the airlaying process and the wet-laid process Fleeces. A personal care product, which contains the material of claim 8, in which at least one layer selected from materials from the group consisting of cellulose fibers, synthetic fibers and whose mixtures are made. The fluid management material of claim 8, wherein the fibrous containment layer has a density between about 0.02 and 0.14 g / cm ³ , the structure is adjacent to the fibrous containment layer, fluid can be exchanged between the structure and the acquisition layer, the structure includes capillary surface materials having capillary surface material fibers and the second fibrous layer is adjacent to the structure and fluid can be exchanged between the structure and the second fibrous layer. The fluid management material according to claim 14, in which at least one layer produced by a method is, selected from the group consisting of the spun-bonding process, the melt-blow process, the co-forming process, the bonded carded fabric process, the Air flow method and the method of forming wet laid Paper towels. The fluid management material according to claim 14, in which more than 75% of fibers of the capillary surface material are aligned in the same direction. The fluid management material according to claim 14, in which the fibers of the structural layer are not round. The fluid management material according to claim 14, which in addition Contains superabsorbent. The fluid management material according to claim 14, which in addition Contains conjugated fibers. The fluid management material according to claim 14, in which the structure contains superabsorbent fibers. A personal care product, which is the fluid management material from claim 14. A feminine hygiene product containing the fluid management material of claim 14, wherein the structure has at least 2 square meters of surface area of the non-round, hydrophilic fibers of the capillary surface material, of which more than 75% is in the same direction in at least one zone which is up to 20 mm wide and has a basis weight of about 50 g / m ² , and wherein the product has a breakthrough time of less than 40 seconds and distributes artificial menses according to a swell / distribution test, with a distribution rate of at least about 0.06.